uses graph;
var draiver, mood, x, y: integer;
begin
  draiver:=Vga; mood:=VgaMed;
  initgraph(draiver, mood, '');
  x:=50;
  repeat
    circle(x, 100, 20);
    x:=x+30;
  until x>600;
  readln;
  closegraph;
end.